<template>
  <div>
      <nav-bar>
          <div slot="left" class="back" @click="backClick">
              <img src="~assets/img/common/back.svg" alt=""/>
          </div>
          <div slot="center" class="title">
              <div v-for="(item, index) in titles" 
              class="title-item" 
              :key="item.id" 
              :class="{active:index === currentIndex}"
              @click="titleClick(index)">
                  {{item}}
              </div>
          </div>
    </nav-bar>
  </div>
</template>

<script>
import NavBar from 'components/common/navbar/NavBar';
export default {
  name: 'DetailNavBar',
  data() { 
    return {
        titles:['商品', '参数', '评论', '推荐'],
        currentIndex: 0,
    }
  },
  components:{
      NavBar
  },
  methods:{
      titleClick(index){
          this.currentIndex = index;
          this.$emit('titleClick', index);
      },
      backClick(){
          this.$router.back();
      }
  }
 }
</script>

<style scoped>
.title{
    display: flex; 
}
.title-item{
    flex: 1;
}
.active{
    color: red;
}
.back img{
    margin-top: 12px;
}
</style>